ajsons

Thanks again, Speakerfritz. This is what EVGuy (Bernie) sent to me. I see these things on ebay often at unreasonably (at least to me) high bids. They seem so easy to duplicate. And probably come up with a better version. Let me take a picture of what I plan to do.

Thanks, Speakerfritz. I didn't realize I was missing some pages. Now I have a complete set. Let me take a picture of what I'm going to do with the crossovers. Rman

Bill, I got the H600 horn last night. Thank you very much. Which brand of beer do you prefer? Armando

Gil, You have a p.m. Rman

I know that. I'm trying to show how I will do it, unforunately I didn't clarify that. It just happened that I have a drawing of a La Scala handy, with some of the changes I'd like to see.. The truth is, I never liked the design. I don't know why I'm even on this thread. I'll use a full Huygen reflector, though. Edit: Actually, I know why I'm on this thread. I've seen most of JC's work and I'm impressed by his accomplishments, esp. the dual 15 corner bass bin. Great job, JC.

The drawing shows a throat 6" wide, duct = 3". Effectively you now have two horns, one going to the left, one to right. Taking the center of the 3" path of the right horn, it is 1-1/2 if you start from the throat going up to the horizontal center. If you start at the center of the board, it is also 1-1/2. So it is the same. Don't ask me what happens if the cutout is 3 x 13. Honestly I can't explain that one.

For simplicity, yes, that's where I'll start, at the center. It gets complicated because of the 3 x 13 cutout. If the motorboard cutout is 6 x 13, then it is much easier to see. Your horn length (total distance traveled, so far, is only 7", not 14. Yes the board width is 14. And you're on the right track as far as changing the dead space into something usable..

Mike, Tractrix bass horn is not the way to go, per Edgar. He says "tractrix bass horn" is a contradiction of terms. http://www.positive-feedback.com/Issue4/edgarinterview.htm " ......so when I built a 70 Hertz Tractrix Bass Horn (Speaker Builder, 1983), I was in for a surprise. The problem is that the Tractrix is a short horn. If you take the equivalent Tractrix and equivalent exponential horns (same mouths, same throats, same flare rates), the Tractrix horn is shorter. At the low end, the response on any horn is limited by the throat reactance, which peaks at the flare frequency. The exponential horn is long enough that if you can put on a back chamber and resonate it with your loudspeaker at the flare frequency, you can partially cancel out that throat reactance. With a hyperbolic exponential horn, you can cancel it out exactly. With a Tractrix horn, you don't cancel it out at all, so the 70-Hertz horn rolled off at 100 Hertz. It sounded very good, but the problem is that the Tractrix horn response just does not extend to the flare point. There is no way that you can do it, so you have to live with the consequences. Well, for a midrange horn that's not too bad. The 300-Hertz horn that I make turns on at around 400 Hertz, and since its size is not huge, I can build a full-size 300-Hertz horn. It sounds very nice, but it won't turn on until 400 Hertz."

JC, A 70hz corner horn is a short horn. A 60hz will be like 34-36" long.

JC, The Jubilee paper shows how to calculate what the area should be at any point along the horn's path (Area analysis of points B, C and D). Dana has a quick and easy way of calculating these. I don't want to deal with the math (my weakness), so I let the pc do it. Here's a sample readout, the expansion for a 70hz corner horn. Pure exponental (M=1). "A" and "B" sides are distances between parallel sidewalls of the horn's duct, i.e under the 6" A side column are the distances between the non-parallel or expanding walls. If you're sure of your final height, let me know I'll rerun the figures with a different fc, dimension for A or B or both. (These are based on Edgar's Show Horn article). 70HZ CORNER HORN Throat = 78 sq inches M = 1 Length Horn One-half 6 inches 38 inches fm throat area area A sides B sides --------- --------- --------- --------- --------- 1 83.25147 41.62574 6.937623 1.095414 2 88.85651 44.42825 7.404709 1.169165 3 94.83891 47.41946 7.903243 1.24788 4 101.2241 50.61205 8.435341 1.331896 5 108.0392 54.01958 9.003263 1.421568 6 115.3131 57.65654 9.609423 1.517277 7 123.0767 61.53835 10.25639 1.61943 8 131.363 65.68152 10.94692 1.728461 9 140.2073 70.10363 11.68394 1.844832 10 149.6469 74.82346 12.47058 1.969038 11 159.7222 79.86108 13.31018 2.101607 12 170.4757 85.23785 14.20631 2.243101 13 181.9532 90.97662 15.16277 2.394121 14 194.2035 97.10176 16.18363 2.55531 15 207.2786 103.6393 17.27322 2.72735 16 221.2339 110.617 18.43616 2.910973 17 236.1289 118.0644 19.67741 3.106959 18 252.0266 126.0133 21.00222 3.31614 19 268.9947 134.4973 22.41622 3.539404 20 287.1052 143.5526 23.92543 3.777699 21 306.435 153.2175 25.53625 4.03204 22 327.0662 163.5331 27.25552 4.303503 23 349.0865 174.5432 29.09054 4.593243 24 372.5893 186.2946 31.0491 4.90249

jc, I've been reading most of Dana's posts, he doesn't post in the weekends, I think he's busy teaching the choir. You have to wait till Monday for his reply. Most of the answer to your questions are on Gil's thread, http://forums.klipsch.com/forums/thread/545202.aspx The throat is 78 sq inches. The motoboard opening is 39 sq inches, the K33 woofer works well with that opening. If you want to use another woofer, most likely you have to use a 78 opening, pretty much "standard" for a 15" woofer.

Bill, You have a p.m. Rman

Thanks, Bob. You're killing me, what is it?

A delayed turn-on for extra capacitance?

A capacitor rejuvenator?

You said the magic word....tuned.

Third page.

These pages are from A. Cohen's "Hi-fi Loudspeakers and Enclosures"

The horn will not function "normally" from the front 'coz now you don't have a compression chamber. My understanding is that the compression chamber in a horn loaded woofer is actually the area in front of the woofer. see attached diagram and look at area vf indentifed as a compression chamber. While I was in europe from 86 to 89, I did a lot of work recovering and re-directing sound waves from the "enclosed" area of speaker cabinets. In this particular senerio, a base bin with an open side, fitted with a horizontal baffle 3/4's the lengths of the base bin, angled as the horrizontal baffle used in the electrovoice aristrocrat, would recover some of the waves while not canceling out the waves from the front. The idea of turning a lascala around and directing the waves into a corner or floor, would result in loss of some of the waves in the mid-bass area. I'm completely aware of THAT compression chamber. Most people don't know that the REAR chamber is also called a compression chamber (see attached), and as far as the La Scala, Klipschorns, etc. etc., it must be completely airtight for reasons stated in the attached pages. What you are describing may work for an Aristocrat, which was specifically designed with that in mind. I doubt that it will work for a La Scala, as it will be a serious LEAK. I will expect a drop in efficiency and loss of the bass frequencies. Spill and recovery is not for me.

The horn will not function "normally" from the front 'coz now you don't have a compression chamber.

Thanks, Dana. Like at my work, it's always nice to have somebody with more design experience to check your drawings. I appreciate your inputs very much. Someday, I'll earn that horn designer badge. Armando

If you have a wooden floor that absorbs a lot of bass energy like Edgar's, or if you want to place the enclosure against a wall, not in a corner, add a pyramidal reflector. The horn exhausts to the front and the two sides.

I wish I have two closets that can hold a couple of these.

It's an interesting construction article so I'm posting the other pages.

Dana, Here's one that pre-dates the Tattersall patent (1987) by about 33 years.. It is a closet horn (never heard of that one) from 1954. Looks like the U.S. had that convergent-divergent throat first before the Aussies. Armando